1-O-acetylbritannilactone combined with gemcitabine elicits growth inhibition and apoptosis in A549 human non-small cell lung cancer cells

Non-small-cell lung cancer (NSCLC) accounts for similar to 85% of all lung cancer cases, with a 5-year survival rate of <15%. 1-O-acetylbritannilactone (ABL), a natural chemical component obtained from inula britannica, a Chinese traditional medicine, has been demonstrated to have anticancer activity. In the present study, the antiproliferative and proapoptotic abilities of ABL alone or in combination with gemcitabine in a human NSCLC cell line were investigated. A549 cells were treated in vitro with ABL, gemcitabine, and a combination of ABL and gemcitabine for 72 h. The results demonstrated that ABL and gemcitabine inhibited cell growth and induced apoptosis of A549 cells. These effects were more potent following the combination of ABL and gemcitabine treatment than either agent alone. Furthermore, the signal transduction analysis revealed nuclear factor (NF)-kappa B expression was significantly decreased by ABL and the combination treatment. The inhibitor nuclear factor kappa B alpha (I kappa B alpha) and Bax levels were upregulated whereas Bc1-2 was substantially downregulated following treatment. The present findings suggest that ABL combined with gemcitabine elicits potent apoptosis of lung cancer cells and therefore, ABL has the potential to be developed as a chemotherapeutic agent.